Time-voltage area of the QRS for the identification of left ventricular hypertrophy.
Academic Article
Overview
abstract
Standard electrocardiographic criteria have exhibited poor sensitivity for left ventricular hypertrophy at acceptable levels of specificity and perform less well in women than men, even when sex-specific criteria are used. The time-voltage integral of the horizontal plane vector QRS complex can improve identification of hypertrophy in men, but performance of this approach in women and the effect of sex-specific criteria on accuracy have not been examined. To evaluate the accuracy of the time-voltage integral of the QRS complex for the identification of left ventricular hypertrophy in women and to examine the effect of sex-and non-sex-specific criteria on test performance, we obtained standard 12-lead and orthogonal-lead signal-averaged electrocardiograms and echocardiograms in 175 control subjects without hypertrophy (43 women and 132 men) and 75 patients with hypertrophy (26 women and 49 men) defined by echocardiographic criteria (indexed left ventricular mass > 110 g/m2 in women and > 125 g/m2 in men). Voltage of the QRS complex was integrated over the total QRS duration in leads X and Z for calculation of the time-voltage integral of the horizontal plane vector complex. With the use of a partition of 99.2 microV.s with a specificity of 98% in the entire normal group, sensitivity of the horizontal plane vector integral was significantly lower in women than men (31% versus 71%, P < .001). In contrast, use of sex-specific partitions of 75.4 microV.s in women and 99.2 microV.s in men with matched 98% specificity significantly improved sensitivity in women to 81% (P < .001), with no change in sensitivity in men (71%). Comparison of receiver operating characteristic curves with the use of sex-specific criteria demonstrated no significant difference in overall performance of the horizontal plane vector integral between men and women. The 81% and 71% sensitivities of the sex-specific horizontal plane vector integral were significantly greater than the 27% to 58% sensitivities of sex-specific 12-lead electrocardiographic criteria in this population. Thus, sex-specific criteria significantly improve performance of the time-voltage integral of the QRS for the identification of left ventricular hypertrophy in women, with no loss of accuracy in men. Use of the time-voltage integral can improve the accuracy of the electrocardiogram for the identification of left ventricular hypertrophy in both women and men.
